Turkmenistan ( or ; , ), formerly known as Turkmenia (Туркмения/Turkmeniya), is one of the Turkic states in Central Asia. Turkmenistan is bordered by Kazakhstan to the northwest, Uzbekistan to the northeast and east, Afghanistan to the southeast, Iran to the south and southwest, and the Caspian Sea to the west. Present-day Turkmenistan covers territory that has been at the crossroads of civilizations for centuries. In medieval times Merv (today known as Mary) was one of the great cities of the Islamic world, and an important stop on the Silk Road, a caravan route used for trade with China until the mid-15th century. Annexed by the Russian Empire in 1881, Turkmenistan later figured prominently in the anti-Bolshevik movement in Central Asia. In 1924, Turkmenistan became a constituent republic of the Soviet Union, Turkmen Soviet Socialist Republic (Turkmen SSR); it became independent upon the dissolution of the Soviet Union in 1991. Turkmenistan’s GDP growth rate of 11% in 2012 comes on the back of several years of sustained high growth, albeit from a very basic undiversified economy powered by export of a single commodity. It possesses the world’s fourth largest reserves of natural gas resources. Although it is wealthy in natural resources in certain areas, most of the country is covered by the Karakum (Black Sand) Desert. Since 1993, citizens have received government-provided electricity, water and natural gas free of charge on a guarantee scheduled to last until 2030. Turkmenistan was ruled by President for Life Saparmurat Niyazov (called “Türkmenbaşy”, “Leader of the Turkmens”) until his sudden death on 21 December 2006. Gurbanguly Berdimuhamedow was elected the new president on 11 February 2007. According to Human Rights Watch, “Turkmenistan remains one of the world’s most repressive countries. The country is virtually closed to independent scrutiny, media and religious freedoms are subject to draconian restrictions, and human rights defenders and other activists face the constant threat of government reprisal.” President Berdymukhamedov promotes a personality cult in which he, his relatives, and associates enjoy unlimited power and total control over all aspects of public life. A natural gas field in the country known as Door to Hell draws frequent media attention and more recently, also touristic interest.